Impact of baryon resonances on the chiral phase transition at finite temperature and density

Zschiesche, D.; Zeeb, G.; Schramm, Stefan; Stöcker, H.

doi:10.1088/0954-3899/31/8/022

Cited by 15 publications

(15 citation statements)

References 59 publications

(126 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Baryon resonances like the ∆ ought to be coupled to chiral fields including their chiral partners. This brings down the chiral condensate of lower temperature as can be seen in [48].…”

Section: The Cmf Model Phase Diagrammentioning

confidence: 86%

Equation of state for hot QCD and compact stars from a mean-field approach

et al. 2020

View full text Add to dashboard Cite

The thermodynamic properties of high temperature and high density QCD-matter are explored within the Chiral SU(3)-flavor parity-doublet Polyakov-loop quark-hadron mean-field model, CMF. The quark sector of the CMF model is tuned to describe the µB = 0 thermodynamics data of lattice QCD. The resulting lines of constant physical variables as well as the baryon number susceptibilities are studied in some detail in the temperature/chemical potential plane. The CMF model predicts three consecutive transitions, the nuclear first-order liquid-vapor phase transition, chiral symmetry restoration, and the cross-over transition to a quark-dominated phase. All three phenomena are cross-over, for most of the T − µB-plane. The deviations from the free ideal hadron gas baseline at µB = 0 and T ≈ 100 − 200 MeV can be attributed to remnants of the liquid-vapor first order phase transition in nuclear matter. The chiral crossing transition determines the baryon fluctuations at much higher µB ≈ 1.5 GeV, and at even higher baryon densities µB ≈ 2.4 GeV, the behavior of fluctuations is controlled by the deconfinement cross-over. The CMF model also describe well the static properties of high µB neutron stars as well as the new neutron star merger observations. The effective EoS presented here describes simultaneously lattice QCD results at µB = 0, as well as observed physical phenomena (nuclear matter and neutron star matter) at T ∼ = 0 and high densities, µB > 1 GeV.

show abstract

“…Baryon resonances like the ∆ ought to be coupled to chiral fields including their chiral partners. This brings down the chiral condensate of lower temperature as can be seen in [48].…”

Section: The Cmf Model Phase Diagrammentioning

confidence: 86%

Equation of state for hot QCD and compact stars from a mean-field approach

et al. 2020

View full text Add to dashboard Cite

show abstract

“…We shall show that the model is able to reproduce not only the sketched qualitative phase structure but also the location of the endpoint. The properties of the high mass states (masses and couplings) are important for the actual location of the chiral phase transition line [8] in the plane of T and µ q .Lattice results show that the susceptibility peaks of the chiral condensate and of the Polyakov loop coincide at µ q = 0 [9] which indicates that for small µ q those transition(s) involve a coupling of the chiral dynamics to the gauge fields, see e.g. [10].…”

mentioning

confidence: 99%

Phase structure in a hadronic chiral model

Zschiesche

Zeeb

Schramm

2007

J. Phys. G: Nucl. Part. Phys.

Self Cite

View full text Add to dashboard Cite

We study the phase diagram of a hadronic chiral flavor-SU(3) model. Heavy baryon resonances can induce a phase structure that matches current results from lattice-QCD calculations at finite temperature and baryon density. Furthermore, we determine trajectories of constant entropy per net baryon in the phase diagram.Understanding hot and baryon-dense QCD matter is of central importance in theoretical and experimental heavy-ion physics. Various effective theories for chiral symmetry restoration predict that a line of first-order phase transitions in the plane of quark-chemical potential µ q versus temperature T ends in a critical point as the chemical potential is lowered (see [1] for a review). Presently, the lattice locates that point at T ≈ 160 MeV, µ q ≈ 120 MeV [2]. The Compressed Baryonic Matter (CBM) experiment at GSI FAIR is planned to perform a dedicated experimental effort to detect that line of firstorder phase transitions in relativistic heavy-ion collisions. It is hoped that by varying experimental parameters like the beam energy one could trigger phase transitions of variable strength (latent heat) and perhaps even locate the expected second-order critical point.Models relying exclusively on order-parameter dynamics typically predict significantly lower chiral phase transition temperatures in baryon-dense matter than those found on the lattice (see e.g. Fig. 6 in [1]). As shown by Gerber and Leutwyler some time ago [3], while heavy hadronic states are suppressed by the Boltzmann factor, their contribution to the energy density at high temperature is substantial. This agrees with other studies using a hadron resonance gas approach, which provides a reasonable description of the thermodynamics obtained on the lattice below the critical temperature [4]. Heavy states also reduce [3] the strong dependence of the "critical temperature" (defined via the peak of a suitable susceptibility) on the pion mass obtained in simple models for chiral order parameter dynamics [5]. The lattice indicates a relatively weak dependence of T c on the pion mass [6].In this Letter we investigate the role of heavy hadronic states on the location of the chiral critical point within a non-linear SU (3) L × SU (3) R chiral model [7]. Here, the phase transition at high temperature and baryon density is "driven" by baryonic resonance degrees of freedom, as suggested by the discussion above. We shall show that the model is able to reproduce not only the sketched qualitative phase structure but also the location of the endpoint. The properties of the high mass states (masses and couplings) are important for the actual location of the chiral phase transition line [8] in the plane of T and µ q .Lattice results show that the susceptibility peaks of the chiral condensate and of the Polyakov loop coincide at µ q = 0 [9] which indicates that for small µ q those transition(s) involve a coupling of the chiral dynamics to the gauge fields, see e.g. [10]. However, within a matrix model for Polyakov loops, the effect of µ q > 0 on the critical t...

show abstract

“…The mass parameters, m 0 , g R , the relative vector coupling r V and the degeneracy represents free parameters, adjusted to reproduce a phase diagram with a critical end-point as suggested by lattice simulations. An extended discussion of the procedure can be found in [4,5]. By maximizing the pressure one obtains self-consistent gap equations for the meson fields, which are solved numerically.…”

Section: Phase Diagram In the Hadronic Modelmentioning

confidence: 99%

Phase structure of strongly interacting matter and simulations of heavy-ion collisions using a quark-hadron model

Schramm¹,

Steinheimer²,

Dexheimer³

et al. 2010

J. Phys. G: Nucl. Part. Phys.

Self Cite

View full text Add to dashboard Cite

Abstract. We consider the phase structure of hadronic and hadron-quark models at finite temperature and density. The basis for the hadronic part is an extension of a flavor-SU(3) σ − ω model. We study the effect on the phase diagram by adding additional hadronic resonances to the model. With the resulting equation of state we investigate heavy-ion collisions using hydrodynamical simulations. In a combined approach we include quarks and the Polyakov loop field in the calculation and study chiral symmetry restoration and the deconfinement transition. The Model DescriptionA key topic in the study of relativistic heavy-ion collisions is the investigation of the phase structure of highly excited strongly-interacting hadronic and quark matter. This includes the phase transition to a chirally symmetric and deconfined phase at high temperatures and/or densities. From the experimental side one approach to study the transition behavior is to use different beam energies to sample the transition region over a range of excitation energies and densities.At zero chemical potential QCD lattice simulations show a smooth cross-over of the system to a phase with deconfinement and chiral symmetry restoration. Some lattice calculations at finite chemical potential suggest the existence of a critical endpoint of a line of first-order phase transition at T ≈ 160 MeV and µ q ≈ 120 MeV [1]. In the following we investigate the consequences of phase structures of that type by considering chiral hadronic and combined hadron-quark models. The model description of the hadronic system contains the lowest baryonic and mesonic SU(3) multiplets. The interaction of the scalar mesons and baryons generates the vacuum masses of the

show abstract

Impact of baryon resonances on the chiral phase transition at finite temperature and density

Cited by 15 publications

References 59 publications

Equation of state for hot QCD and compact stars from a mean-field approach

Equation of state for hot QCD and compact stars from a mean-field approach

Phase structure in a hadronic chiral model

Phase structure of strongly interacting matter and simulations of heavy-ion collisions using a quark-hadron model

Contact Info

Product

Resources

About